We use these coasters to mark whose cups are whose. With 6 people in the house drinking water all day, we go through a lot of cups. Reusing a cup throughout the day is difficult as no one remembers whose cup that is sitting on the counter and we don't like to share germs. So we got these coasters. Each of us have a our own design so I know if a cup is sitting on the yellow star fruit it is mine. 7 different designs means this will work for all but the largest of families, and they are really inexpensive.